Mortar Mix clean up

[quintain]

I have (stupidly) got 3 adjacent areas, about 1msq a lot of sand & cement mortar mix on my 1850-ish slate floor.
The slate is old but has been stored outside for about 25years so no polish on it.
I am considering scraping as much as possible of the dried mix off and then using soapy water to try to scrub it clean.
Is there a better way of cleaning up the dried mortar marking.

 

[Sachakins]

I think scrape off what you can safely remove without damaging slate, then just soapy water and a stiff bristle scrubbing brush.
Don't know of any proprietary cleaners, but stick clear of acidic cleaners, bleach cleaners and any oxidising cleaning agent as the could damage or cause discoloration and staining.

I know slate is hard-wearing and tough, but being natural untreated stone I would use the gentlest of soapy water and stiff bristles only.

 

[niall Y]

I would have thought brick cleaner would do it. This is usually a dilute hydrochloric acid, Spirits-of-salt, as used for cleaning loos is the same thing - though this will probably need diluting further.
I re laid a slate floor for a customer, and used a lime mortar for bedding them in, and for grouting, so as to match existing areas. This was a lot easier to clean up with clean water, as it took much longer to go off.
With some stone floors and some of the quarry tiled ones you, can apply a dressing to the top surface before laying them, that way you do not get that horrible stained surface. Though if you are careful you only have to do this after the floor is laid and before the grouting itself.

 

[Jones]

If it's old slate in the UK it will be good low carbonate stone. An acid brick cleaner used neat will be ok to use and will be effective and won't stain, bleach or degrade it at all .

 

[ChaiLatte]

Find a place that won't be seen and contaminate it in the same way as the other places. Experiment with your chosen chemical in that place. If it is successful, great; if not, try some other concoction.

 

[eribaMotters]

Brick acid would be my choice. I even used it to remove dry mortar splattered over a vinyl kitchen floor.

Colin